1. Field of the Invention
The present invention relates to measurement devices and measurement methods for obtaining images, such as functional images, structural images, etc., for a measurement subject using various types of magnetic resonances, such as an electron spin resonance (ESR), nuclear magnetic resonance (NMR), etc.
2. Description of the Related Art
Redox metabolism, including active oxygen and free radicals, is closely involved in many physiological phenomena and disease components and progress. Thus, if it is possible to make redox dynamics visible at the individual level, in small experimental animals, there is no doubt that this would greatly contribute to the clarification of vital phenomena, the analysis of disease, the establishment of therapeutic methods for such diseases, and the development of drugs.
Electron spin resonance imaging (ESRI), which specifically detects free radicals, which are intermediate products of redox metabolism, is effective in making redox dynamics visible. However, ESRI images are lacking when it comes to handling internal organs. In order to solve this problem, ESRI/MRI integrated magnetic resonance image analysis devices have been developed that overlay MRI images of internal organs obtained using the nuclear magnetic resonance imaging method (MRI) on the ESRI image.
The Overhauser effect is the phenomenon of the electron spins of free radicals being made to undergo ESR transition, and nuclear spins are polarized through dipolar operation of electron spins and nuclear spins. OMRI is an imaging method wherein an MRI measurement is performed by exciting the electron spins of free radicals and then polarizing the spins of the hydrogen nuclei of water molecules. In OMRI, the nuclear spin polarization is strengthened by a maximum (theoretical value) factor of 330 relative to the normal Boltzmann distribution of nuclear spin. That is to say, it is possible to achieve a 330-fold (theoretical value) improvement in sensitivity relative to an ordinary MRI measurement.
The present applicants have proposed in Japanese Unexamined Patent Application Publication 2006-204551, a biometric device for obtaining histological images of organisms using various types of magnetic resonance, including electron spin resonance, nuclear magnetic resonance, etc. This biometric device includes a first magnetic field generation device that generates a magnetic field of a set size, a second magnetic field generation device that generates a magnetic field that is larger than the magnetic field of this first magnetic field generation device, a linear movement device that causes the organism that is the subject of measurement to move linearly between the first and second magnetic field generation devices in synchronization with the radiation of RF pulses, and a measurement processing device that stops the organism that is the subject of measurement and measures histological images of the organism that is the subject of measurement based on signals that are detected according to the RF pulses.
In this biometric device, the first magnetic field generation device can be used as an ESRI external magnetic field generation device and a PEDRI (OMRI) electron spin excitation device, and the second magnetic field generation device as an MRI and OMRI external magnetic field generation device, so that the time variable images of the radical amount can be obtained as OMRI, and the qualitative alteration images can be obtained as four-dimensional spectrum/spatial ESRI/MRI; since the magnetic field from the second magnetic field generation device can be made larger, high-sensitivity, high-resolution images can be obtained.
Incidentally, with this biometric device, the organism that is the subject of measurement is moved repetitively by the linear movement device provided between the first and second magnetic field generation devices, and measurement is performed after the organism is stopped, so large acceleration is generated when moving and stopping the organism. Thus, there is the problem that a large load is imposed on the moving organism to be measured by this biometric device.
The purpose of the present invention is to provide a measurement device and measurement method that allows the load on the organism that is the subject of measurement to be eliminated by measuring the organism that is the subject of measurement without stopping it as it moves through multiple magnetic field generation devices.